The release of collagenase from cornea. We intend to find evidence for our hypothesis that the collagenase released in traumatized vitamin A-deficient corneas is derived from polymorphonuclear neutrophils (PMN's). This will be done by preventing the invasion of the traumatized corneas by PMN's using a plastic covering, and assaying for collagenase at different times after trauma; by cutting out the traumatized area (central) and the non-traumatized area (peripheral) of the cornea from deficient and normal rats and assaying for collagenase. In both types of experiments, histological sections will be made to back up the biochemical findings. Stimulation of corneal glycoprotein by retinol. We have prepared rat retinol-binding protein and will incubate this with corneas of vitamin A-deficient rats to study glycoprotiens released into the medium.